commit 9426cd05 upstream.

del_timer_sync() cannot be used in interrupt.
Replace it with del_timer() and a flag
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>